t.Fatalf("ReadRune(%U) after UnreadRune got %U,%d not %U,%d (err=%s)", r, r2, nbytes, r, size, err)
		}
	}
}

func TestWriteInvalidRune(t *testing.T) {
	// Invalid runes, including negative ones, should be written as
	// utf8.RuneError.
	for _, r := range []rune{-1, utf8.MaxRune + 1} {
		var buf Buffer
		buf.WriteRune(r)
		check(t, fmt.Sprintf("TestWriteInvalidRune (%d)", r), &buf, "\uFFFD")

continue     for          import       return       var
</pre>

<h3 id="Operators_and_punctuation">Operators and punctuation</h3>

<p>
The following character sequences represent <a href="#Operators">operators</a>
(including <a href="#Assignment_statements">assignment operators</a>) and punctuation
[<a href="#Go_1.18">Go 1.18</a>]:
</p>
<pre class="grammar">
+    &amp;     +=    &amp;=     &amp;&amp;    ==    !=    (    )